High-frequency signaling



Apr. 24, 1923. 1,452,957

E. H. COLPITTS HIGH FREQUENCY SIGNALING Filed Aug. 23 1916 Amp/ #04 1 l 3 ,1 ln 5 em for: fdw/n H fo/p ifis.

Patented Apr. 24, 19 23.

UNITED STATES PATENT OFFICE.

' EDWIN H. COLPITTS, OF EAST ORANGE, NEW JERSEY, ASSIGNOR TO WESTERN ELEG- TRIC COMPANY, INCORPORATED, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

HIGH-FREQUENCY SIGNALING.

Application filed August 23, 1916. Serial No. 116,447.

To all whom it may concern:

Be it known that I, EDWIN H. CoLPrrrs, a subject of the King of Great Britain, re-

' siding at East Orange, in the county of Essex and State of New Jersey, have invented certain new and useful Improvements in High-Frequency Signaling, of which the following is a full, clear, concise, and exact description.

This invention relates to high frequency signaling and more particularly to the relaying or repeating of telephonic messages transmitted by means of high frequency carrier oscillations modulated in accordance with the form of the message wave.

It is anaabject of the invention to provide a system for two-way repeating and to prevent at a repeating station, a .useless local objectionable phenomenon known as singing.

The inventionprovides for accomplishing this by receiving at a repeating station a.

modulated wave transmitted from either or both of two terminal stations. On receiving a modulated wave at the repeating station, a new carrier frequency is substituted having a value different from the carrier frequency for which the repeating stations receiving apparatus is tuned. In other words the receiving apparatus at' the repeating station will not be receptive to the carrier wave transmitted from that repeating station, and the objectionable local circulation of power is prevented. However, the new carrier wave is received at the' proper terminal station.

For a detailed description of various-systems which may be used in practising the invention, reference may be made to the drawing in which Figs. 1, 2 and 3 show difi'erent systems in which a wireless repeating station is intermediate two wire terminal stations.

To illustrate ,how the invention may be practised it is "proposed to use amplifiers, modulators and rectifiers. However, no details of these elements areshown as the invention does not relate to these details, and furthermore, many amplifying, modu ating and rectifyin 'If desired, there may be used the modu ating systemshown in the patent to C01 itts 1,137 ,384, April 27, 1915, or in the U. S. atent to Van der Bijl for high frequency sigschemes are known. for} naling, No. 1,350,752, patented August 24, 1920. According to the disclosure of the latter patent the high and low frequency oscillations are impressed on the input circuit of a 3-element vacuum tube, the output circuit of which transmits the modulated oscillations. The patent to Arnold 1,129,942, Mar. 2, 1915, discloses an amplifier of the audion type which may be used in the repeating system, although any'suitable amplifier may be used.

In Fig. 1 is shown the 2-way wireless repeating station R intermediate the terminal stations A and B. The line L at terminal A is amociated with the high frequency generator 1 and the modulator 2 by means of the transformer 3. Low frequency signal' oscillations, controlling impulses or other variation currents transmitted by line L then modulate oscillations of high frequency l furnished by generator 1. The modulated oscillations are amplified by amplifier 4 and transmitted to the sending conductor 5 by transformer 6. The signals sent from antenna 5 are received at repeating station R by antenna 7 which is coupled to detector 8 by means of transformer 9. Detector 8 is also inductively associated with the high frequency generator 10 and the modulator 11 by means of transformer 12.

The modulated oscillations of frequency 1 are detected by detector 8 and the low frequency detected oscillations are used to modulate oscillations of high frequency 7e supplied by generator 10. The modulator 11 is connected to an amplifier 13 and the amplified oscillations of frequency 7., are transferred tovthe antenna 15 by means of trans- "signal energy is sent out over line L but the balancing network eliminates any potential difference which might otherwise send current to transformer 22 of the local sending apparatus.

It will be apparent then that low frelations of frequency quency signals originating in line L modulate oscillations of frequency 1 which are transmitted from antenna 5 and received at the repeating station. Here the modulated oscillations of frequency 1 are detected and the detected oscillationsare utilized to modulate oscillations of frequency 7. In this manner, modulated carrier oscillations are combined with electrical energy of differentcharacteristic so as to change the carrier frequency of the carrier'oscillations. Since the frequencies and k represent different frequencies the energy transmitted from the repeating station will not affect the local receiving apparatus. The modulated oscilk, are received at terminal B detected and the detected oscillations are sent over the line L to a suitable receiving apparatus.

To provide for two-way transmission the line L, is coupled to modulator 24 and to a high frequency generator 23 ;by transformer 22. The modulator 24 isgassociated with an amplifier 25 the latter being coupled to antenna 26 by transformer 27. Low frequency signals in line L then modulate oscillations of hi h frequency 1 supplied by generator 23 an the modulated oscillations are amplified by amplifier 25 and transmitted from antenna At repeating station R, the antenna 7 is coupled to detector 28 by means of transformer 29. The detector 28 is also coupled to modulator 30 and generator 31 by transformer 32. The output circuit .of modulator 30 is connected to amplifier 13 which as above described supplies amplified oscillations to antenna 15- through transformer 14. The oscillations of frequenc 1;, sent from antenna 26 are then received by antenna 7 detected by detector 28 and the detected oscillations modulate oscillations of high freguency 7. supplied by generator 31. I The mo ulated oscillations after traversing the amplifier 13 are transmitted from antenna. 15 to be received at terminal station A by antenna 33. I

Consequently antenna 7 serves not onl to receive at frequency from terminal 1' but also at the frequency 1 from terminal B. The oscillations of frequencies 1 and 1 are detected and the detected oscillations respectively modulate the frequencies 1., and 7. Modulated oscillations of the latter frequencies are supplied to the common amplifier and transmitted to the proper terminal,

stationsl.

The receiving apparatus at terminal A is similar to that at terminal B and comprises detector 34, the input circuitof which is coupled toanten'na 33 by transformer 35,

' the detector 'outputcircuit bein coupled to "line thro h he agency 0 the transformers 36 an 37; These transformers and the artificial line 38 provide a balancing 26 to the repeating station. I

mea er network for the line L so that energy received by antenna 33 will be sent out onto line L without affecting the transformer 3 in the local sending apparatus.

To eliminate the necessity of having two generators at the repeating station and the consequent necessity o repeating. at two different frequencies, the system shown in Fig. 2 may be employed. In Fig. 2 the terminal station A is identical with A in Fig. 1, both terminals A and A sending at frequency k, and receiving at frequency 1,. The sending apparatus at terminal station 13 is identical with the sending apparatus at terminal B the sending frequency 1 being employed. The terminal B however, is adapted to receive at frequency 1 this being the only frequency transmitted from the repeating station R where both the received frequencies 1 and K are detected, and the detected oscillations used to modulate oscillations of high frequency X supplied by generator 31. For both frequencies X and a are provided the common modulator 39 and the common am lifier 40.

twill be. a parent then that signals may be transmitte from line L .to L and vice versa as in Fig. 1.

A further simplification may be made by transmitting at the same frequencies from the two terminal stations and by repeating at a single different frequency. Such a system is shown in Fig. 3 in which the terminal A is identical with terminals A and A Furthermore, the wireless sending and receiving apparatus at terminal B is identical with the corres ding ap aratus at terminal A Both ermi'nals and B send at the frequency 1 and receive at the frequency 1,. In this case, however, it is only necessary to use a single detector 41 at the repeating station R While by way of illustration my invention has been shown as applied to a wireless aw system, it is to be understood that it is just as applicable to a system in which the signals are transmitted along wires instead of through the those. skilled in the art that controliling "impulses or the energy of other variation currents may be" transmitted "by, this. system in the same manner. The invention is therefore not to be limited to the particular system and features of the system-disclosed but. only by the scope'of the a pended claims.

' What is claime 1s: 7 1. In combination, two widely separated stations each comprising "a two-wire twospace between the stations. It I will moreover be obvious to 115.

way telephone line, a balancing network simulating the" impedance of said line connected to a terminal thereof, means including an antenna for transmitting high frequency waves modified in accordance with the other of said stations.

2. In a signaling system, the combination of two terminal stations each tcomprising a wireless telephone transmitting and receiving system adapted to transmit and receive modulated carrier oscillations, and an intermediate two-way wireless telephone repeating system comprising an antenna adapted to receive modulated carrier oscillations'from both said terminal stations, means associated with saidv antenna for translating the received oscillations, a generator of carrier oscillations, a modulator, means for impressing the translated and the generated oscillations on the input circuit of said modulator, the output circuit of said I modulator being associated with an antenna adapted to transmit modulated oscillations to both of said terminal stations.

3. In a signaling system, the combination of two terminal stations each comprising a wireless telephone transmitting and receiv ing system adapted to transmit and receive modulated carrier oscillations, and an intermediate two-way wireless telephone repeating system'comprising an antenna adapted to receive modulated carrier oscillations from both said terminal stations, means associated with said antenna for translating the received oscillations, a generator of carrier oscillations of frequency different from that -of said received oscillations, a modulator,

means for impressing the translated and the generated oscillations on the input circuit of said modulator, the output circuit of said modulator being associated with an antenna .adapted to transmit modulated oscillations of changed frequency to both of said terminal stations.

4. In combination, two widely separated transmission systems each comprising a two- 5 wire circuit, a balancing network of similar impedance characteristic connected to said circuit at its terminal, high frequency transmitting apparatus and high frequency receiving apparatus connected to said circuit and network conjugately with respect to each other, said transmitting apparatus com prising means for modifying a high he quency carrier wave in accordance with currents received over said circuit without interrupting the continuity of said wave, said receiving apparatus comprising means for receiving a modified carrier wave detecting it and impressing the detected wave upon said circuit, and an intermediate two-way repeating apparatus for repeating energy transmitted from one system to the receiving apparatus of the other system including means for changing the frequency of the carrier wave as repeated.

5. Means for carrying on a two way telephonic conversation between two widely separated points comprising an antenna for transmitting signals, a source of high frequency energy and apparatus for controlling the same connected to said antenna, a receiving antenna having suitable receiving apparatus operatively connected thereto at all times and separated from said transmitting antenna and diflerently tuned so that the effect of the transmitted signals may be eliminated in the receiving apparatus, a telephone line, means for connecting the telephone line simultaneously to both the transmitting and receiving apparatus, a second telephone line, means for connecting the second telephone line to two separate antennae arranged in a manner similar to the first mentioned antennae, and a two-way radio repeating apparatus intermediate said two widely separated points for repeating energy transmitted from each of said points to the other of said points.

' In witness whereof, I hereunto subscribe my name this 15th day of August A. 'D.,

'EDWIN- H. COLPITTS. 

